Alert archive / Kentucky / Tornado Watches in 2021

Tornado Watch 55

March 25, 202125 counties in Kentucky; 20 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Mar 25, 2021, 9:26 PM CDT for 25 counties in Kentucky; 20 counties in Tennessee. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Mar 25, 2021, 9:26 PM CDT (02:26 UTC)
Expired
Mar 25, 2021, 11:47 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 45 counties

Adair County, KY, Boyle County, KY, Casey County, KY, Clinton County, KY, Cumberland County, KY, Estill County, KY, Garrard County, KY, Green County, KY, Jackson County, KY, Jessamine County, KY, Knox County, KY, Laurel County, KY, Lincoln County, KY, Madison County, KY, Marion County, KY, McCreary County, KY, Mercer County, KY, Nelson County, KY, Pulaski County, KY, Rockcastle County, KY, Russell County, KY, Taylor County, KY, Washington County, KY, Wayne County, KY, Whitley County, KY, Anderson County, TN, Bledsoe County, TN, Bradley County, TN, Campbell County, TN, Cumberland County, TN, Fentress County, TN, Hamilton County, TN, Knox County, TN, Loudon County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sequatchie County, TN, Union County, TN

The radar

The Jackson,KY radar (KJKL), 128 km from the middle of the area, began a volume at 02:25 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
30%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
10%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
60%

Warnings issued inside it

8 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Mar 25, 9:42 PM CDTSevere Thunderstorm WarningLMKHardin, Hart, Larue, Nelson33 min
Mar 25, 9:45 PM CDTTornado WarningLMKHardin, Larue, Nelson30 min
Mar 25, 9:57 PM CDTTornado WarningLMKClinton15 min
Mar 25, 10:01 PM CDTSevere Thunderstorm WarningLMKBoyle, Green, Larue, Marion, Mercer, Nelson and 2 more29 min
Mar 25, 10:02 PM CDTSevere Thunderstorm WarningJKLMcCreary, Pulaski, Wayne28 min
Mar 25, 10:03 PM CDTTornado WarningLMKMarion, Nelson, Washington27 min
Mar 25, 10:06 PM CDTTornado WarningJKLPulaski, Wayne24 min
Mar 25, 10:25 PM CDTTornado WarningJKLPulaski, Wayne12 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 00:00Z, 2.4 hours before the alert went out and 208 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Nashville Metro, TN at 00:00Z on 2021-03-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 290 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 00:00Z on 2021-03-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 657 square meters per square second.1939587897117136Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
290 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
615 m above ground
0-6 km bulk shear
85 kt
0-1 km storm-relative helicity
657 m²/s²
0-3 km storm-relative helicity
631 m²/s²
Significant tornado parameter
1.0
Supercell composite
7.4

Open this sounding in Storm Lab

The text

As transmitted.

120 
WWUS20 KWNS 260223
SEL5  
SPC WW 260223
KYZ000-TNZ000-260600-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 55
NWS Storm Prediction Center Norman OK
1025 PM EDT Thu Mar 25 2021

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Eastern Kentucky
  Eastern Tennessee

* Effective this Thursday night and Friday morning from 1025 PM
  until 200 AM EDT.

* Primary threats include...
  A couple tornadoes possible
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...Multiple clusters should move east from central Kentucky
and Middle Tennessee with a continued threat for a couple tornadoes
and scattered damaging winds.

The tornado watch area is approximately along and 50 statute miles
east and west of a line from 25 miles east northeast of Lexington KY
to 60 miles south southwest of Crossville TN. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU5).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.

&&

OTHER WATCH INFORMATION...CONTINUE...WW 51...WW 52...WW 53...WW
54...

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 1 inch. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean
storm motion vector 24045.

...Grams

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 25, 9:07 PM CDTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Boone, Boyle and 40 more83 min
Mar 25, 7:00 PM CDTMesoscale DiscussionSPCFranklin, Giles, Lawrence, Lincoln, Wayne30 min
Mar 25, 7:36 PM CDTMesoscale DiscussionSPCBedford, Cannon, Coffee, Davidson, DeKalb, Grundy and 11 more84 min
Mar 25, 7:57 PM CDTTornado WatchSPCFranklin, Giles, Lawrence, Lincoln, Moore, Wayne3 hr

Nearby

Tornado Watches in Kentucky, 2021Tornado Watches in Tennessee, 2021Every tornado watch in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.